Flexible packages

ABSTRACT

A flexible pouch having an openable closure comprising a closure element arranged to close an opening in the pouch, at least one edge part of the opening being folded relative to the remainder of the body, and a seal for detachably sealing said one edge part of the opening by adhesion to at least one overlapping edge part of said closure element, the seal being produced by coating at least one of the surfaces where the seal is to be provided with an adhesive which is reactivatable by the application of heat and/or pressure.

United States Patent 1 Foster FLEXIBLE PACKAGES Norman Foster, Millbank, London SW. 1, England [73] Assignee: British-American Tobacco Company Limited, London, England 221 Filed: Oct; 14, 1971 21 Appl. No.: 189,147

[75] Inventor:

[30] Foreign Application Priority Data Oct 19, 1970 Great Britain 49,565/70 [52] [1.8. Cl. 229/62, 206/56 AA [51] Int. Cl B65d 33/16 [58] Field of Search 229/62, 3.5 MP, 69;

206/DIG. 18, 56 AA, 56 AB [56] References Cited UNITED STATES PATENTS 10/1966 Platt 229/62 7/1964 Heigl 229/62 10/1963 Lipschutz et al. 229/62 1451 June 12, 1973.

3,561,670 2/1971 Segal 229/3.5 MF 3,613,874 10/1971 Miller A 229/62 2,582,286 1/1952 Schenck .1 229/62 3,047,347 7/1962 Groves 206/56 AB 3,396,902 8/1968 Kilgore 229/62 Primary Examiner George E. Lowrance Assistant ExaminerAlan Eskenas Attorney-Kane, Dalsimer, Kane, Sullivan and Kurucz I [57] ABSTRACT A flexible pouch having an openable closure comprising a closure element arranged to close an opening in the pouch, at least one edge part of theopening being folded relative to the remainder oil the body, and a seal for detachably sealing said one edge part of the opening by adhesion to at least one overlapping edge part of said closure element, the seal being produced by coating at least one of the surfaces where the seal is to be provided with an adhesive which is reactivatable by the application of heat and/or pressure.

4 Claims, 8 DrawingFigures' Patented June 12, 1973 7 3,738,566

1 FLEXIBLE PACKAGES This invention relates to improvements in flexible pouches and is particularly but not exclusively, concerned with pouches for tobacco or tobacco products. The invention is however applicable to bags for food products such as potato crisps, sweets and flour confectionary.

According to the present invention there is provided a flexible pouch having an openable closure comprising a closure element inserted in or laid over an opening in the pouch at least one edge part of the opening being folded inwardly or outwardly and a seal for detachably sealing said one edge part of the opening by adhesion to at least one overlapping edge part of the said closure element.

Preferably each seal is produced by coating at least one of the surfaces where the seal or seals is to be provided with an adhesive which is reactivatable by the application of heat and/or pressure. The peel strength of the bond thus formed is designed to be low compared with the tensile strength or elastic limit of the material, so that the latter will not be damaged when the seal is peeled open. Any temperature applied in making the seal should be lower than the melting point of the material.

Such a pouch or bag can be opened simply by gripping and pulling on the closure element in such a manner as to peel the seal open. In this manner a seal can easily be opened without damaging the material. On the other hand the seal will provide protection for the contents of the pouch against environmental effects,

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawing in which:

FIG. 1 shows part of a pouch in accordance with the invention with the closure element partially removed,

FIGS. 2 to 6 show various embodiments of pouch in cross-section,

FIG. 7 shows a plurality of bags made from a continuous length of material and FIG. 8 shows an alternative layout of forming a plurality of bags from a continuous length of material.

The pouch shown in FIG. 1 comprises a flat rectangular bag 10 made, for example, from two sheets of transparent plastics material secured permanently together along the bottom and side edges 11. The bag has along its open top edge narrow marginal portions or top edges 12 folded outwardly to lie adjacent the outer surfaces of the sheets as shown in FIG. 2. A closure element in the form of a cap 13 is made of two strips 14 of plastics material secured permanently together along one edge. The cap 13 is applied over the top of the bag so that narrow marginal portions of the strips 14 overlap externally the top edges 12 of the bag itself as shown in FIG. 2. Prior to such application an adhesive I is coated upon either or both of the marginal portions between which the seal is formed. The seal is made by subjecting the overlapping marginal portions to heat and/or pressure, as required by the adhesive used. In one form the bag is made of cellulose film and the adhesive is nitro-cellulose or a copolymer of vinyl chloride and vinylidene chloride such as SARAN. The seals are formed by the application of a hot bar or wheel having a surface temperature of l35-l40C. By applying the adhesive coating to both surfaces of the seals the vapour impermeability is improved but production problems, such as the formation of undesirable additional seals, might arise. The bag can readily be opened without damage by pulling on the upper portion of the cap 13 so as to peel open the seals.

In another form the pouch is made of polypropylene film coated with vinylidene chloride copolymer such as Propafilm C or alternatively of aluminium foil coated with polyethylene and provided with a pressuresensitive adhesive coating such as a latex based compound.

In the embodiment shown in FIG. 3 the cap 13 is formed from a single strip of material folded on itself.

In the embodiment shown in FIG. 4, the cap 13 is also formed from a single strip of material but the marginal portions of the bag are folded inwardly, the marginal portions of the cap being inserted inside the bag to a position aligned with the marginal portions of the bag. In contrast to the arrangements shown in FIGS. 2 and 3, in FIG. 4 the adhesive coating is applied to the external surface of the bag.

In the aove described examples, the closure element can be removed completely from the bag. For some purposes, however, it may be preferred that the closure element should remain attached to the bag after opening so that the closure element can. be folded over after opening to act as a flap to provide some protection for a part of the contents not required for immediate use. FIG. 5 shows one such embodiment, the closure elementor cap 13 being formed integrally with one of the side Walls 15 of the bag. A seal is produced between overlapping marginal portions of the cap 13 at its free edge and the upper edge of the outwardly folded part of the other side wall 16. An additional seal 17 is provided between a fold 18 produced in the said one side wall at the transition between the body of the bag and the closure element or cap itself to form substantially symmetrically located seals at the front and back of the bag. Such a bag may be especially suitable for use as a tobacco-containing pouch.

The caps 13 described above with reference to FIGS. 1 to 4 are formed of separate parts of material but, as shown in the embodiment illustrated in FIG. 6, may be initially made between parts of a fold or folds in one piece of material, the crest 19 of the or each fold being subsequently cut away or split along the length of the fold. In this case the bag may conveniently be made from a flat length of material.

Such an arrangement is advantageous when it is desired to produce bags from a continuous length of material. FIG. 7 illustrates one arrangement for producing multiple-bag units using a continuous length of material. In this embodiment the several folds extend longitudinally along the material, adjacent units sharing common seals 20 affording permanent connections at the side edges of the bags both in the body of the bag and the closure element itself. At the mid-point of the connecting seals 20 lines of perforations are provided so that the bags may be readily separated from the continuous length of material.

FIG. 8 illustrates an alternative arrangement in which a plurality of bags are produced by separate parallel folds formed transversely to the length of the material, adjacent bags being joined at the bottom by common sealed sections 22. The sealed sections 22 have perforated lines 23 at their midwidths so that individual bags, each having a permanent seal at its bottom edge, may be detached from the length of material.

It will be appreciated that many combinations of the above described embodiments may be made. It will also be understood that alternative materials may be used such as polyethylene, polyester, polystyrene, nylon metal foil, paper or a laminate of various combinations of materials, providing that the peel strength of the bond is arranged to be low compared with the strength of the material so that the bag will not be damaged when the seal is peeled open.

A pouch having a closure element which is retained to form a closure flap would be useful for contents consumed over a period of days after opening, such as pipe tobacco. Preferably, for pipe tobacco the pouch is made of a paper/metal-foil laminate with the metal foil on the inside of the bag.

Pouches according to the present invention have direct application in the consumer industries, particularly for foodstuffs, including confectionary or flour confectionary requiring to be packed into flexible, fully sealed, pouch or pillow packs. Particularly for this purpose, the adhesive used for making the seals should in this case be of a type which will have no effect on the taste or other characteristics of the contents.

It will be understood that many variations may be made to the shape and configuration of the pouches; for example the caps may be folded to form shoulders or pleats above the marginal parts thereof which form the seals.

I claim:

1. A flexible pouch having a body, an openable closure comprising a closure element arranged to close an opening in the pouch body at least one edge part of the opening being folded relative to the remainder of the body and a seal for detachably sealing said one edge part of the opening by adhesion to at least one overlapping edge part of the said closure element, the seal being produced by coating at least one of the surfaces where the seal is to be provided with an adhesive which is reactivatable by the application of heat, the closure element being formed of a single strip of material, seals being provided at opposed side edges of the strip for sealing with opposed edge parts of the opening, the pouch being formed from a length of material, the closure element being formed by appropriate spaced folds in the material adhesive being inserted in the folds, and the crest of the folds bieng severed to enable the closure element to be detachable.

2. The invention in accordance with claim 1 wherein a plurality of inter-coupled pouches are formed from a continuous length of material, a permanent seal being formed between adjacent pouches, the permanent seal having a perforated line therein to enable a pouch to be detached without unsealing any of the pouches.

3. The invention in accordance with claim 1 wherein the closure element forms a flap to close the opening after the seal has been broken, the pouch being adapted to receive tobacco and being formed of. a paper/metal foil laminate with the metal foil on the inside of the pouch.

4. The invention in accordance with claim 2 wherein the closure element forms a flap to close the opening after the seal has been broken, the pouch being adapted to receive tobacco and being formed of a paper/metal foil laminate with the metal foil on the inside ofthe pouch. 

1. A flexible pouch having a body, an openable closure comprising a closure element arranged to close an opening in the pouch body at least one edge part of the opening being folded relative to the remainder of the body and a seal for detachably sealing said one edge part of the opening by adhesion to at least one overlapping edge part of the said closure element, the seal being produced by coating at least one of the surfaces where the seal is to be provided with an adhesive which is reactivatable by the application of heat, the closure element being formed of a single strip of material, seals being provided at opposed side edges of the strip for sealing with opposed edge parts of the opening, the pouch being formed from a length of material, the closure element being formed by appropriate spaced folds in the material adhesive being inserted in the folds, and the crest of the folds bieng severed to enable the closure element to be detachable.
 2. The invention in accordance with claim 1 wherein a plurality of inter-coupled pouches are formed from a continuous length of material, a permanent seal being formed between adjacent pouches, the permanent seal having a perforated line therein to enable a pouch to be detached without unsealing any of the pouches.
 3. The invention in accordance with claim 1 wherein the closure element forms a flap to close the opening after the seal has been broken, the pouch being adapted to receive tobacco and being formed of a paper/metal foil laminate with the metal foil on the inside of the pouch.
 4. The invention in accordance with claim 2 wherein the closure element forms a flap to close the opening after the seal has been broken, the pouch being adapted to receive tobacco and being formed of a paper/metal foil laminate with the metal foil on the inside of the pouch. 